evalphobia/aws-sdk-go-wrapper

package config

import (
    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/aws/credentials"
    "github.com/aws/aws-sdk-go/aws/session"

    "github.com/evalphobia/aws-sdk-go-wrapper/private/pointers"
)

const defaultRegion = "us-east-1"

// Config has AWS settings.
type Config struct {
    AccessKey string
    SecretKey string
    Region    string
    Endpoint  string

    // Filename and Profile are used for file credentials
    Filename string
    Profile  string

    // DefaultPrefix is used for service resource prefix
    // e.g.) DynamoDB table, S3 bucket, SQS Queue
    DefaultPrefix string

    // Specific sevice's options
    S3ForcePathStyle bool

    // optional
    CredentialsChainVerboseErrors     bool
    DisableComputeChecksums           bool
    DisableEndpointHostPrefix         bool
    DisableParamValidation            bool
    DisableRestProtocolURICleaning    bool
    DisableSSL                        bool
    EC2MetadataDisableTimeoutOverride bool
    EnableEndpointDiscovery           bool
    EnforceShouldRetryCheck           bool
    LowerCaseHeaderMaps               bool
    S3Disable100Continue              bool
    S3UseAccelerate                   bool
    S3DisableContentMD5Validation     bool
    S3UseARNRegion                    bool
    UseDualStack                      bool

    UseMaxRetries bool
    MaxRetries    int
}

// Session creates AWS session from the Config values.
func (c Config) Session() (*session.Session, error) {
    return session.NewSession(c.AWSConfig())
}

// AWSConfig creates *aws.Config object from the fields.
func (c Config) AWSConfig() *aws.Config {
    cred := c.awsCredentials()
    awsConf := &aws.Config{
        Credentials: cred,
        Region:      pointers.String(c.getRegion()),
    }

    ep := c.getEndpoint()
    if ep != "" {
        awsConf.Endpoint = &ep
    }

    if c.S3ForcePathStyle {
        awsConf.S3ForcePathStyle = pointers.Bool(true)
    }

    if c.CredentialsChainVerboseErrors {
        awsConf.CredentialsChainVerboseErrors = pointers.Bool(true)
    }
    if c.DisableComputeChecksums {
        awsConf.DisableComputeChecksums = pointers.Bool(true)
    }
    if c.DisableEndpointHostPrefix {
        awsConf.DisableEndpointHostPrefix = pointers.Bool(true)
    }
    if c.DisableParamValidation {
        awsConf.DisableParamValidation = pointers.Bool(true)
    }
    if c.DisableRestProtocolURICleaning {
        awsConf.DisableRestProtocolURICleaning = pointers.Bool(true)
    }
    if c.DisableSSL {
        awsConf.DisableSSL = pointers.Bool(true)
    }
    if c.EC2MetadataDisableTimeoutOverride {
        awsConf.EC2MetadataDisableTimeoutOverride = pointers.Bool(true)
    }
    if c.EnableEndpointDiscovery {
        awsConf.EnableEndpointDiscovery = pointers.Bool(true)
    }
    if c.EnforceShouldRetryCheck {
        awsConf.EnforceShouldRetryCheck = pointers.Bool(true)
    }
    if c.LowerCaseHeaderMaps {
        awsConf.LowerCaseHeaderMaps = pointers.Bool(true)
    }
    if c.S3Disable100Continue {
        awsConf.S3Disable100Continue = pointers.Bool(true)
    }
    if c.S3UseAccelerate {
        awsConf.S3UseAccelerate = pointers.Bool(true)
    }
    if c.S3DisableContentMD5Validation {
        awsConf.S3DisableContentMD5Validation = pointers.Bool(true)
    }
    if c.S3UseARNRegion {
        awsConf.S3UseARNRegion = pointers.Bool(true)
    }
    if c.UseDualStack {
        awsConf.UseDualStack = pointers.Bool(true)
    }
    if c.UseMaxRetries && c.MaxRetries >= 0 {
        awsConf.MaxRetries = &c.MaxRetries
    }

    return awsConf
}

func (c Config) awsCredentials() *credentials.Credentials {
    // from env
    cred := credentials.NewEnvCredentials()
    _, err := cred.Get()
    if err == nil {
        return cred
    }

    // from param
    if c.AccessKey != "" && c.SecretKey != "" {
        return credentials.NewStaticCredentials(c.AccessKey, c.SecretKey, "")
    }

    // from local file
    if c.Filename != "" {
        return credentials.NewSharedCredentials(c.Filename, c.Profile)
    }

    // IAM role
    return nil
}

func (c Config) getRegion() string {
    if c.Region != "" {
        return c.Region
    }
    reg := EnvRegion()
    if reg != "" {
        return reg
    }
    return defaultRegion
}

func (c Config) getEndpoint() string {
    if c.Endpoint != "" {
        return c.Endpoint
    }
    ep := EnvEndpoint()
    if ep != "" {
        return ep
    }
    return ""
}